@mr_kaza 

Hi, thank you very much for posting on TP-Link Community.

Please connect a computer to your ISP modem directly and check if internet works fine for all websites.

If so, please then connect the ISP modem back to WAN port of the TP-Link router, if the router still has the same issue, please check if there is WAN or Internet IP address on the router, if so, try changing Internet IP address manually to 8.8.8.8: